Cancer is the second leading cause of death in the U.S. Despite very active research in the area, the number of deaths related to cancer has not fallen significantly in the past decade. A major problem associated with the development of effective treatments is due to long time scales required for monitoring of in-vivo cancer behavior in a laboratory or clinical setting. The current advancements in theoretical biology however, have created a unique possibility to conduct many such statics in-silico, using computer-based numerical simulations. We propose to develop high-fidelity software tools to enable such simulations. One of the keys to tumor control is tumor vascularization through angiogenesis. Mathematical models of the angiogenic processes and the resultant tumor response already exist and can describe the system dynamics on both macro and micro-scales. The proposed software will incorporate these models in a hierarchical structure coupling the macro and micro behavior ranging from the general macro-level tumor development to microlevel vascularization details. Such a model will have the potential to dramatically reduce the study and development of cancer treatments to be measured in hours and days and not months as is currently the case. It will also allow in-silico investigation of treatments that are not practical in-vivo, or are limited by time constraints.